vary.c revision 59022
131921Sbrian/*- 231921Sbrian * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org> 331921Sbrian * All rights reserved. 431921Sbrian * 531921Sbrian * Redistribution and use in source and binary forms, with or without 631921Sbrian * modification, are permitted provided that the following conditions 731921Sbrian * are met: 831921Sbrian * 1. Redistributions of source code must retain the above copyright 931921Sbrian * notice, this list of conditions and the following disclaimer. 1031921Sbrian * 2. Redistributions in binary form must reproduce the above copyright 1131921Sbrian * notice, this list of conditions and the following disclaimer in the 1231921Sbrian * documentation and/or other materials provided with the distribution. 1331921Sbrian * 1431921Sbrian * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1531921Sbrian * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1631921Sbrian * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1731921Sbrian * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1831921Sbrian * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1931921Sbrian * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2031921Sbrian * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2131921Sbrian * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2231921Sbrian * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2331921Sbrian * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2431921Sbrian * SUCH DAMAGE. 2531921Sbrian */ 2631921Sbrian 2735773Scharnier#ifndef lint 2835773Scharnierstatic const char rcsid[] = 2950471Speter "$FreeBSD: head/bin/date/vary.c 59022 2000-04-05 01:59:36Z brian $"; 3035773Scharnier#endif /* not lint */ 3135773Scharnier 3227874Sbrian#include <time.h> 3327874Sbrian#include <string.h> 3427874Sbrian#include <stdlib.h> 3527874Sbrian#include "vary.h" 3627874Sbrian 3727874Sbrianstruct trans { 3827874Sbrian int val; 3927874Sbrian char *str; 4027874Sbrian}; 4127874Sbrian 4227874Sbrianstatic struct trans trans_mon[] = { 4327874Sbrian { 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" }, 4457326Salfred { 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" }, 4557326Salfred { 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" }, 4627874Sbrian { -1, NULL } 4727874Sbrian}; 4827874Sbrian 4927874Sbrianstatic struct trans trans_wday[] = { 5027874Sbrian { 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" }, 5127874Sbrian { 4, "thursday" }, { 5, "friday" }, { 6, "saturday" }, 5227874Sbrian { -1, NULL } 5327874Sbrian}; 5427874Sbrian 5527874Sbrianstatic char digits[] = "0123456789"; 5659022Sbrianstatic int adjhour(struct tm *, char, int); 5727874Sbrian 5827874Sbrianstatic int 5959022Sbriandomktime(struct tm *t, char type) 6059022Sbrian{ 6159022Sbrian int ret; 6259022Sbrian 6359022Sbrian /* 6459022Sbrian * Don't let mktime have a specific tm_isdst value. If we do, 6559022Sbrian * it gets confused when we ``vary'' in and out of Summer time 6659022Sbrian */ 6759022Sbrian t->tm_isdst = -1; 6859022Sbrian if ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138) 6959022Sbrian /* 7059022Sbrian * If mktime() fails, adjust by an hour. If we're actually 7159022Sbrian * bridging a savings of several hours, we'll recurse several 7259022Sbrian * times. 7359022Sbrian */ 7459022Sbrian ret = adjhour(t, type == '-' ? type : '+', 1); 7559022Sbrian 7659022Sbrian return ret; 7759022Sbrian} 7859022Sbrian 7959022Sbrianstatic int 8027874Sbriantrans(const struct trans t[], const char *arg) 8127874Sbrian{ 8227874Sbrian int f; 8327874Sbrian 8427874Sbrian for (f = 0; t[f].val != -1; f++) 8528025Sbrian if (!strncasecmp(t[f].str, arg, 3) || 8628025Sbrian !strncasecmp(t[f].str, arg, strlen(t[f].str))) 8727874Sbrian return t[f].val; 8827874Sbrian 8927874Sbrian return -1; 9027874Sbrian} 9127874Sbrian 9227874Sbrianstruct vary * 9328025Sbrianvary_append(struct vary *v, char *arg) 9427874Sbrian{ 9527874Sbrian struct vary *result, **nextp; 9627874Sbrian 9727874Sbrian if (v) { 9827874Sbrian result = v; 9927874Sbrian while (v->next) 10027874Sbrian v = v->next; 10127874Sbrian nextp = &v->next; 10227874Sbrian } else 10327874Sbrian nextp = &result; 10427874Sbrian 10527874Sbrian *nextp = (struct vary *)malloc(sizeof(struct vary)); 10627874Sbrian (*nextp)->arg = arg; 10727874Sbrian (*nextp)->next = NULL; 10827874Sbrian return result; 10927874Sbrian} 11027874Sbrian 11127874Sbrianstatic int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 11227874Sbrian 11327874Sbrianstatic int 11427874Sbriandaysinmonth(const struct tm *t) 11527874Sbrian{ 11627874Sbrian int year; 11727874Sbrian 11827874Sbrian year = t->tm_year + 1900; 11927874Sbrian 12027874Sbrian if (t->tm_mon == 1) 12127874Sbrian if (!(year % 400)) 12227874Sbrian return 29; 12327874Sbrian else if (!(year % 100)) 12427874Sbrian return 28; 12527874Sbrian else if (!(year % 4)) 12627874Sbrian return 29; 12727874Sbrian else 12827874Sbrian return 28; 12927874Sbrian else if (t->tm_mon >= 0 && t->tm_mon < 12) 13027874Sbrian return mdays[t->tm_mon]; 13127874Sbrian 13227874Sbrian return 0; 13327874Sbrian} 13427874Sbrian 13527874Sbrian 13627874Sbrianstatic int 13727874Sbrianadjyear(struct tm *t, char type, int val) 13827874Sbrian{ 13927874Sbrian switch (type) { 14027874Sbrian case '+': 14127874Sbrian t->tm_year += val; 14227874Sbrian break; 14327874Sbrian case '-': 14427874Sbrian t->tm_year -= val; 14527874Sbrian break; 14627874Sbrian default: 14727874Sbrian t->tm_year = val; 14827874Sbrian if (t->tm_year < 69) 14927874Sbrian t->tm_year += 100; /* as per date.c */ 15027874Sbrian else if (t->tm_year > 1900) 15127874Sbrian t->tm_year -= 1900; /* struct tm holds years since 1900 */ 15227874Sbrian break; 15327874Sbrian } 15459022Sbrian return domktime(t, type) != -1; 15527874Sbrian} 15627874Sbrian 15727874Sbrianstatic int 15827874Sbrianadjmon(struct tm *t, char type, int val, int istext) 15927874Sbrian{ 16027874Sbrian if (val < 0) 16127874Sbrian return 0; 16227874Sbrian 16327874Sbrian switch (type) { 16427874Sbrian case '+': 16546073Simp if (istext) { 16627874Sbrian if (val <= t->tm_mon) 16727874Sbrian val += 11 - t->tm_mon; /* early next year */ 16827874Sbrian else 16927874Sbrian val -= t->tm_mon + 1; /* later this year */ 17046073Simp } 17159022Sbrian if (val) { 17259022Sbrian if (!adjyear(t, '+', (t->tm_mon + val) / 12)) 17359022Sbrian return 0; 17459022Sbrian val %= 12; 17559022Sbrian t->tm_mon += val; 17659022Sbrian if (t->tm_mon > 11) 17759022Sbrian t->tm_mon -= 12; 17859022Sbrian } 17927874Sbrian break; 18027874Sbrian 18127874Sbrian case '-': 18246073Simp if (istext) { 18327874Sbrian if (val-1 > t->tm_mon) 18427874Sbrian val = 13 - val + t->tm_mon; /* later last year */ 18527874Sbrian else 18627874Sbrian val = t->tm_mon - val + 1; /* early this year */ 18746073Simp } 18859022Sbrian if (val) { 18959022Sbrian if (!adjyear(t, '-', val / 12)) 19027874Sbrian return 0; 19159022Sbrian val %= 12; 19259022Sbrian if (val > t->tm_mon) { 19359022Sbrian if (!adjyear(t, '-', 1)) 19459022Sbrian return 0; 19559022Sbrian val -= 12; 19659022Sbrian } 19759022Sbrian t->tm_mon -= val; 19827874Sbrian } 19927874Sbrian break; 20027874Sbrian 20127874Sbrian default: 20227874Sbrian if (val > 12 || val < 1) 20327874Sbrian return 0; 20427874Sbrian t->tm_mon = --val; 20527874Sbrian } 20627874Sbrian 20759022Sbrian return domktime(t, type) != -1; 20827874Sbrian} 20927874Sbrian 21027874Sbrianstatic int 21127874Sbrianadjday(struct tm *t, char type, int val) 21227874Sbrian{ 21327874Sbrian int mdays; 21459022Sbrian 21527874Sbrian switch (type) { 21627874Sbrian case '+': 21727874Sbrian while (val) { 21827874Sbrian mdays = daysinmonth(t); 21927874Sbrian if (val > mdays - t->tm_mday) { 22027874Sbrian val -= mdays - t->tm_mday + 1; 22127874Sbrian t->tm_mday = 1; 22227874Sbrian if (!adjmon(t, '+', 1, 0)) 22327874Sbrian return 0; 22427874Sbrian } else { 22527874Sbrian t->tm_mday += val; 22627874Sbrian val = 0; 22727874Sbrian } 22827874Sbrian } 22927874Sbrian break; 23027874Sbrian case '-': 23127874Sbrian while (val) 23227874Sbrian if (val >= t->tm_mday) { 23327874Sbrian val -= t->tm_mday; 23427874Sbrian t->tm_mday = 1; 23527874Sbrian if (!adjmon(t, '-', 1, 0)) 23627874Sbrian return 0; 23727874Sbrian t->tm_mday = daysinmonth(t); 23827874Sbrian } else { 23927874Sbrian t->tm_mday -= val; 24027874Sbrian val = 0; 24127874Sbrian } 24227874Sbrian break; 24327874Sbrian default: 24427874Sbrian if (val > 0 && val <= daysinmonth(t)) 24527874Sbrian t->tm_mday = val; 24627874Sbrian else 24727874Sbrian return 0; 24827874Sbrian break; 24927874Sbrian } 25027874Sbrian 25159022Sbrian return domktime(t, type) != -1; 25227874Sbrian} 25327874Sbrian 25427874Sbrianstatic int 25528025Sbrianadjwday(struct tm *t, char type, int val, int istext) 25627874Sbrian{ 25727874Sbrian if (val < 0) 25827874Sbrian return 0; 25927874Sbrian 26028025Sbrian switch (type) { 26127874Sbrian case '+': 26227874Sbrian if (istext) 26327874Sbrian if (val < t->tm_wday) 26427874Sbrian val = 7 - t->tm_wday + val; /* early next week */ 26527874Sbrian else 26627874Sbrian val -= t->tm_wday; /* later this week */ 26727874Sbrian else 26859022Sbrian val *= 7; /* "-v+5w" == "5 weeks in the future" */ 26959022Sbrian return !val || adjday(t, '+', val); 27027874Sbrian case '-': 27159022Sbrian if (istext) { 27227874Sbrian if (val > t->tm_wday) 27327874Sbrian val = 7 - val + t->tm_wday; /* later last week */ 27427874Sbrian else 27527874Sbrian val = t->tm_wday - val; /* early this week */ 27659022Sbrian } else 27759022Sbrian val *= 7; /* "-v-5w" == "5 weeks ago" */ 27859022Sbrian return !val || adjday(t, '-', val); 27927874Sbrian default: 28027874Sbrian if (val < t->tm_wday) 28127874Sbrian return adjday(t, '-', t->tm_wday - val); 28227874Sbrian else if (val > 6) 28327874Sbrian return 0; 28427874Sbrian else if (val > t->tm_wday) 28527874Sbrian return adjday(t, '+', val - t->tm_wday); 28627874Sbrian } 28727874Sbrian return 1; 28827874Sbrian} 28927874Sbrian 29027874Sbrianstatic int 29128025Sbrianadjhour(struct tm *t, char type, int val) 29227874Sbrian{ 29359022Sbrian /* 29459022Sbrian * We've got to be careful here in case 29559022Sbrian * domktime() calls 29659022Sbrian * adjhour() calls 29759022Sbrian * adjday() calls 29859022Sbrian * domktime() calls 29959022Sbrian * adjhour() and recurses forever. It's vital that we've adjusted our 30059022Sbrian * number of hours before calling adjday(). 30159022Sbrian */ 30259022Sbrian 30328025Sbrian if (val < 0) 30428025Sbrian return 0; 30528025Sbrian 30628025Sbrian switch (type) { 30727874Sbrian case '+': 30859022Sbrian if (val) { 30959022Sbrian int days; 31059022Sbrian 31159022Sbrian days = (t->tm_hour + val) / 24; 31259022Sbrian val %= 24; 31359022Sbrian t->tm_hour += val; 31459022Sbrian t->tm_hour %= 24; 31559022Sbrian if (!adjday(t, '+', days)) 31659022Sbrian return 0; 31759022Sbrian } 31828025Sbrian break; 31928025Sbrian 32027874Sbrian case '-': 32159022Sbrian if (val) { 32259022Sbrian int days; 32359022Sbrian 32459022Sbrian days = val / 24; 32559022Sbrian val %= 24; 32659022Sbrian if (val > t->tm_hour) { 32759022Sbrian days++; 32859022Sbrian val -= 24; 32959022Sbrian } 33059022Sbrian t->tm_hour -= val; 33159022Sbrian if (!adjday(t, '-', val / 24)) 33228025Sbrian return 0; 33328025Sbrian } 33428025Sbrian break; 33528025Sbrian 33627874Sbrian default: 33728025Sbrian if (val > 23) 33828025Sbrian return 0; 33928025Sbrian t->tm_hour = val; 34027874Sbrian } 34128025Sbrian 34259022Sbrian return domktime(t, type) != -1; 34327874Sbrian} 34427874Sbrian 34528025Sbrianstatic int 34628025Sbrianadjmin(struct tm *t, char type, int val) 34728025Sbrian{ 34828025Sbrian if (val < 0) 34928025Sbrian return 0; 35028025Sbrian 35128025Sbrian switch (type) { 35228025Sbrian case '+': 35359022Sbrian if (val) { 35459022Sbrian if (!adjhour(t, '+', (t->tm_min + val) / 60)) 35559022Sbrian return 0; 35659022Sbrian val %= 60; 35759022Sbrian t->tm_min += val; 35859022Sbrian if (t->tm_min > 59) 35959022Sbrian t->tm_min -= 60; 36059022Sbrian } 36128025Sbrian break; 36228025Sbrian 36328025Sbrian case '-': 36459022Sbrian if (val) { 36559022Sbrian if (!adjhour(t, '-', val / 60)) 36628025Sbrian return 0; 36759022Sbrian val %= 60; 36859022Sbrian if (val > t->tm_min) { 36959022Sbrian if (!adjhour(t, '-', 1)) 37059022Sbrian return 0; 37159022Sbrian val -= 60; 37259022Sbrian } 37359022Sbrian t->tm_min -= val; 37428025Sbrian } 37528025Sbrian break; 37628025Sbrian 37728025Sbrian default: 37828025Sbrian if (val > 59) 37928025Sbrian return 0; 38028025Sbrian t->tm_min = val; 38128025Sbrian } 38228025Sbrian 38359022Sbrian return domktime(t, type) != -1; 38428025Sbrian} 38528025Sbrian 38644598Sbrianstatic int 38744598Sbrianadjsec(struct tm *t, char type, int val) 38844598Sbrian{ 38944598Sbrian if (val < 0) 39044598Sbrian return 0; 39144598Sbrian 39244598Sbrian switch (type) { 39344598Sbrian case '+': 39459022Sbrian if (val) { 39559022Sbrian if (!adjmin(t, '+', (t->tm_sec + val) / 60)) 39659022Sbrian return 0; 39759022Sbrian val %= 60; 39859022Sbrian t->tm_sec += val; 39959022Sbrian if (t->tm_sec > 59) 40059022Sbrian t->tm_sec -= 60; 40159022Sbrian } 40244598Sbrian break; 40344598Sbrian 40444598Sbrian case '-': 40559022Sbrian if (val) { 40659022Sbrian if (!adjmin(t, '-', val / 60)) 40744598Sbrian return 0; 40859022Sbrian val %= 60; 40959022Sbrian if (val > t->tm_sec) { 41059022Sbrian if (!adjmin(t, '-', 1)) 41159022Sbrian return 0; 41259022Sbrian val -= 60; 41359022Sbrian } 41459022Sbrian t->tm_sec -= val; 41544598Sbrian } 41644598Sbrian break; 41744598Sbrian 41844598Sbrian default: 41944598Sbrian if (val > 59) 42044598Sbrian return 0; 42144598Sbrian t->tm_sec = val; 42244598Sbrian } 42344598Sbrian 42459022Sbrian return domktime(t, type) != -1; 42544598Sbrian} 42644598Sbrian 42727874Sbrianconst struct vary * 42827874Sbrianvary_apply(const struct vary *v, struct tm *t) 42927874Sbrian{ 43028025Sbrian char type; 43128025Sbrian char which; 43228025Sbrian char *arg; 43328025Sbrian int len; 43428025Sbrian int val; 43528025Sbrian 43627874Sbrian for (; v; v = v->next) { 43728025Sbrian type = *v->arg; 43828025Sbrian arg = v->arg; 43928025Sbrian if (type == '+' || type == '-') 44028025Sbrian arg++; 44128025Sbrian else 44228025Sbrian type = '\0'; 44328025Sbrian len = strlen(arg); 44428025Sbrian if (len < 2) 44528025Sbrian return v; 44628025Sbrian 44728025Sbrian if (strspn(arg, digits) != len-1) { 44828025Sbrian val = trans(trans_wday, arg); 44928025Sbrian if (val != -1) { 45028025Sbrian if (!adjwday(t, type, val, 1)) 45128025Sbrian return v; 45228025Sbrian } else { 45328025Sbrian val = trans(trans_mon, arg); 45428025Sbrian if (val != -1) { 45528025Sbrian if (!adjmon(t, type, val, 1)) 45628025Sbrian return v; 45728025Sbrian } else 45827874Sbrian return v; 45928025Sbrian } 46028025Sbrian } else { 46128025Sbrian val = atoi(arg); 46228025Sbrian which = arg[len-1]; 46328025Sbrian 46428025Sbrian switch (which) { 46544598Sbrian case 'S': 46644598Sbrian if (!adjsec(t, type, val)) 46744598Sbrian return v; 46844598Sbrian break; 46928025Sbrian case 'M': 47028025Sbrian if (!adjmin(t, type, val)) 47128025Sbrian return v; 47228025Sbrian break; 47328025Sbrian case 'H': 47428025Sbrian if (!adjhour(t, type, val)) 47528025Sbrian return v; 47628025Sbrian break; 47728025Sbrian case 'd': 47828025Sbrian if (!adjday(t, type, val)) 47928025Sbrian return v; 48028025Sbrian break; 48128025Sbrian case 'w': 48228025Sbrian if (!adjwday(t, type, val, 0)) 48328025Sbrian return v; 48428025Sbrian break; 48528025Sbrian case 'm': 48628025Sbrian if (!adjmon(t, type, val, 0)) 48728025Sbrian return v; 48828025Sbrian break; 48928025Sbrian case 'y': 49028025Sbrian if (!adjyear(t, type, val)) 49128025Sbrian return v; 49228025Sbrian break; 49328025Sbrian default: 49427874Sbrian return v; 49528025Sbrian } 49627874Sbrian } 49727874Sbrian } 49827874Sbrian return 0; 49927874Sbrian} 50027874Sbrian 50127874Sbrianvoid 50227874Sbrianvary_destroy(struct vary *v) 50327874Sbrian{ 50427874Sbrian struct vary *n; 50527874Sbrian 50627874Sbrian while (v) { 50727874Sbrian n = v->next; 50827874Sbrian free(v); 50927874Sbrian v = n; 51027874Sbrian } 51127874Sbrian} 512